The goal of this project is to evaluate the chronic toxicity and carcinogenicity of dietary zinc in rats. Zinc carbonate basic was used to supply zinc, an essential element and supplement, in the diet. Some studies suggest that zinc deficiency is associated with carcinogenicity. 2-Year chronic dosed- feed toxicity and carcinogenicity studies are in the histopathology/report writing phase. The diets used in this study were either zinc deficient, contained an adequate amount of zinc or contained excess zinc. Keywords: toxicity, carcinogenicity, diet, zinc, zinc carbonate basic